Seaweed Farming Research Articles

Seaweed Growth Monitoring with a Low-Cost Vision-Based System.

In this paper, we introduce a method for automated seaweed growth monitoring by combining a low-cost RGB and stereo vision camera. While current vision-based seaweed growth monitoring techniques focus on laboratory measurements or above-ground seaweed, we investigate the feasibility of the underwater imaging of a vertical seaweed farm. We use deep learning-based image segmentation (DeeplabV3+) to determine the size of the seaweed in pixels from recorded RGB images. We convert this pixel size to meters squared by using the distance information from the stereo camera. We demonstrate the performance of our monitoring system using measurements in a seaweed farm in the River Scheldt estuary (in The Netherlands). Notwithstanding the poor visibility of the seaweed in the images, we are able to segment the seaweed with an intersection of the union (IoU) of 0.9, and we reach a repeatability of 6% and a precision of the seaweed size of 18%.

Risiko Produksi Dan Harga Pada Usahatani Rumput Laut Di Kabupaten Takalar Provinsi Sulawesi Selatan

Seaweed is an export product of aquaculture commodities that have high economic value. One of the areas with high seaweed production in Indonesia is Takalar Regency, South Sulawesi Province. The challenges faced in seaweed farming in South Sulawesi are productivity and price fluctuations. This indicates that there is a risk in cultivated seaweed farming. This study aimed to analyze production risk factors, price risk levels, and risk management for seaweed farming in Takalar Regency, South Sulawesi Province. This study uses primary data derived from 100 respondents who were selected randomly. Analysis of production risk factors using the Just and Pope models with the Cobb-Douglas production function and the level of price risk is carried out by measuring the coefficient of variation and the price floor. Meanwhile, risk management consists of preventive, mitigation, and risk-coping strategies. The results showed that the production risk factors that had a significant effect was labor and harvesting age and had the characteristic of inducing risk factors. The price risk farmers face in Takalar Regency is indicated by the coefficient variation value of 0,279, so the risk level faced is 27,9 percent per kg. Risk management is a preventive strategy by maximizing farming activities, and the quality of the inputs used before risks occur in production and prices.

Evidence of elevated heavy metals concentrations in wild and farmed sugar kelp (Saccharina latissima) in New England

Seaweed farming in the United States is gaining significant financial and political support due to prospects to sustainably expand domestic economies with environmentally friendly products. Several networks are seeking appropriate synthesis of available science to both inform policy and substantiate the sector’s sustainability claims. Significant knowledge gaps remain regarding seaweed-specific food hazards and their mitigation; a resource-intensive challenge that can inhibit sustainable policies. This is particularly concerning for rapidly expanding Saccharina latissima (sugar kelp) crops, a brown seaweed that is known to accumulate heavy metals linked to food hazards. Here, we present baseline information about concentrations of arsenic, cadmium, lead, and mercury, in both wild and farmed sugar kelp from the New England region. We interpret our findings based on proximity to potential sources of contamination, location on blade, and available heavy metals standards. Contrary to our expectations, high concentrations were widespread in both wild and farmed populations, regardless of proximity to contamination. We find, like others, that cadmium and arsenic consistently reach levels of regulatory concern, and that dried seaweeds could harbor higher concentrations compared to raw products. We also share unique findings that suggest some toxins concentrate at the base of kelp blades. Our results are one step towards aggregating vital data for the region to expand its seaweed farming footprint.

Tropical Red Macroalgae Cultivation with a Focus on Compositional Analysis.

To create carbon efficient sources of bioenergy feedstocks and feedstuff for aquaculture and terrestrial livestock, it is critical to develop and commercialize the most efficient seaweed cultivation approach with a sustainable nutrient input supply. Here, we present data for a novel, onshore tropical macroalgae cultivation system, based on influent deep seawater as the nutrient and carbon sources. Two red algal species were selected, Agardhiella subulata and Halymenia hawaiiana, as the basis for growth optimization. Highest productivity in small-scale cultivation was demonstrated with A. subulata in the 10% deep seawater (64.7 µg N L-1) treatment, growing at up to 26% specific growth rate day-1 with highest yields observed at 247.5 g m-2 day-1 fresh weight. The highest yields for H. hawaiiana were measured with the addition of 10% deep seawater up to 8.8% specific growth rate day-1 and yields at 63.3 g fresh weight m-2 day-1 equivalent. Biomass should be culled weekly or biweekly to avoid density limitations, which likely contributed to a decrease in SGR over time. With a measured 30-40% carbon content of the ash-free dry weight (20-30% of the dry weight) biomass, this translates to an almost 1:1 CO2 capture to biomass ratio. The compositional fingerprint of the high carbohydrate content of both Agardhiella and Halymenia makes for an attractive feedstock for downstream biorefinery applications. By focusing on scaling and optimizing seaweed farming technologies for large-scale onshore farms, the opportunities for yield potential, adaptability to cultivation conditions, and meeting global sustainability goals through novel, carbon-negative biomass sources such as seaweed can be realized.

Efforts to Increase Local Community Income Through Seaweed Cultivation in Arareni Village Yapen Islands Regency

Papua has various kinds of potential marine natural resource wealth, both biological and non-biological natural wealth. The potential of these natural resources should be utilized to improve the community's economy. Utilization of the potential of marine resources is still far from expectations. One of the potential marine resources is seaweed. Seaweed has export potential, and its economic value is met from cultivation activities. The aim of this community partnership empowerment (PKM) activity is to increase the knowledge of small-scale seaweed farmers and implement pre-harvest seaweed cultivation practices in Arareni Village, Yapen Islands Regency. The approach used is the delivery of material through socialization related to cultivation practices, starting from the land preparation process, seeding, maintenance, calculating harvest time and yields, as well as group management. During the socialization there were also questions and answers and discussions. The success of the activity is evaluated through a pre-post test. The results show that the highest increase in knowledge was achieved in the cultivation process material (pre-test 47% and post-test 61%). Seaweed farmers know that the seed production age is 25-30 days, harvest after 30-45 days, seed weight 50-100 grams, maintenance takes 25-30 days, distance between ropes 100-200 cm, seeds must be 20-50 cm apart below the water surface and the yield size is 250 g/rope.

Transfer Teknologi Pengayaan Bibit Rumput Laut Yang Dibudidayakan Dengan Keramba Jaring Apung

Inappropriate cultivation methods and a decrease in the quality of seaweed seeds are some of the obstacles in seaweed production. Technology transfer activities through community service programs aim to provide learning to seaweed farmers on how to enrich seaweed seeds with bionic fertilizer and then cultivate them using the floating net cage method. The activity was carried out on August 24-25, 2022 at the Main Base Command Headquarters of the Indonesian Navy VII Kupang. The method used was a participatory empowerment approach involving seaweed farming communities with counseling and dissemination. Seaweed cultivation with the floating net cage method showed higher absolute growth, relative growth and daily growth rate compared to the longline method, which were 11.91 ± 0.69 g day-1, 0.032 ± 0.002 g g-1 day-1 and 3.14 ± 0.17% day -1, respectively. While in the longline method, it was 9.48±1.81 g day-1, 0.027±0.004 g g-1 day-1, and 2.65±0.43% day -1, respectively.

Technical efficiency with stochastic production function frontier of seaweed farming in Pantai Amal, Tarakan City

Efficiency in production is very important to produce optimal production. An important factor in carrying out production efficiency is the use of inputs or production factors so as to produce optimal output. This is often called technical efficiency. The sampling technique was carried out using a non-probability sampling method, while the method or technique used is purposive sampling, with certain considerations, namely: seaweed farmers who have been farming for at least 1 year, the farmer’s age is at least 17 years. The number of samples was carried out by quota as many as 60 seaweed farmers. Methods of data analysis Technical efficiency is analyzed using the stochastic frontier production function, in this case the form of the production function is the Cobb Douglass production function. The results showed (1) the factors that affect the technical efficiency of seaweeds are land area, amount of seeds, labor force, age, education, and farming experience. (2) The average level of technical efficiency of seaweed farmers in Tarakan City in general is 0.974 (efficient). The factor that can reduced technical inefficiency was education. education has a negative relationship and was significant in increasing technical efficiency.

Supporting ecosystem services of habitat and biodiversity in temperate seaweed (Saccharina spp.) farms

Habitat provisioning, and the biodiversity within, is considered a type of “supporting” ecosystem service. Ecosystem services are the benefits humans receive from healthy ecosystems. We assess whether kelp (Saccharina spp.) farms provide seasonal habitat for wild organisms. Contrary to other studies conducted in tropic seaweed farms, we did not observe habitat provisioning or increased biodiversity at seasonal temperate seaweed farm sites compared to neighboring non-farm sites, which is encouraging news for the aquaculture industry given that most farm gear is removed from the water after the spring harvest. We quantified fish and crustaceans interacting with kelp farms using GoPro cameras. We also assessed small (<5 mm) invertebrates using mesh settling devices suspended at the same depth as kelp lines (2m). Visual surveys were paired with eDNA. There was coherence in the conclusions drawn from observational and eDNA methods, despite weak coherence in the specific species identified between the methods. Both farm and non-farm sites exhibited higher species richness and biodiversity in the summer non-growing season compared to the winter growing season, attributed to expected seasonal species movements.

Economic Behavior of Seaweed Farmers' Households in Pasikolaga Sub District Muna District

This study aims to determine the economic behavior of seaweed cultivator households in Kolese Village, Pasikolaga District, Muna Regency. This research was conducted in Kolese Village, Pasikolaga District, Muna Province. Household economics includes a discussion of household economic behavior regarding production, working hours, income, and household consumption expenditures. The survey subjects were 47 people, carried out by simple random sampling. zc The data analysis used is a quantitative descriptive analysis method. Based on the research results, the average income of seaweed cultivators is 1,608 kg/year. The time spent growing seaweed reached 4.81%, packing seaweed reached 25.42%, and drying time reached 3.53%. The average household income earned by farmers is IDR. 18,924,818. The average expenditure for food was IDR. 269,647, while for non-food expenditure, it was IDR. 767,987.

SEAWEED CULTURE, POST-HARVEST PROCESSING, AND MARKET GENERATION FOR EMPLOYMENT OF COASTAL POOR COMMUNITIES IN COX'S BAZAR

Seaweed farming is one of the aquaculture industries with the greatest growth rate worldwide, with an annual production of over 33 billion tonnes, and a value of USD$11.8 billion which is predicted to treble by 2024. The current study was conducted in the Bakkhali River estuary and set out to survey the seaweed cultivation, processing, marketing status of the seaweed farmers and evaluate its financial benefits. Gracilaria lemaneiformis and Ulva intestinalis were cultured using the rope methods. The yield of G. lemaneiformis and U. intestinalis was good (Ten 15 m long ropes were used in each of the 45 plots, produced 7770 kg of G. lemaneiformis in the first 15 days while using ten 15 m long ropes were in each of the plots of U. intestinalis produced 2300 kg). Water parameters viz. temperature, salinity, pH, DO and transparency were checked every 15 days. According to previous literature, winter was determined to be the most productive time for seaweed development in Bangladesh. Seaweed was processed by the sun drying method and sold to retail clients, neighborhood shops and markets, and representatives in Cox's Bazar, Bandarban, Rangamati and Khagrachari district, where G. lemaneiformis attracting the higher price. The income of seaweed farmers has increased more than in the previous years to maintain their family. Most of the farmers used raw seaweed as traditional medicine for the treatment of gastric problem (80%), diabetes (5%), blood pressure (3%) and cancer (2%). They also used seaweed as an additive with other vegetables, mutton and chicken. Education for coastal people is very difficult, but after cultivating seaweed, about 60% of farmers can afford their children's education cost and about 85% of the households had electric fans, while the majority had mobile phones. The cost-benefit analysis demonstrated that seaweed cultivation is highly profitable.

Recent Advances in Seaweed Biorefineries and Assessment of Their Potential for Carbon Capture and Storage

Seaweeds are among the most important biomass feedstocks for the production of third-generation biofuels. They are also efficient in carbon sequestration during growth and produce a variety of high-value chemicals. Given these characteristics together with the relatively high carbohydrate content, seaweeds have been discussed as an ideal means for CO2 capture and biofuel production. Though third-generation biofuels have emerged as some of the best alternatives to fossil fuels, there is currently no large-scale production or mainstream use of such liquid fuels due to the many technical challenges and high production costs. The present study describes the concept of coastal marine biorefineries as the most cost-effective and sustainable approach for biofuel production from seaweeds, as well as atmospheric carbon capture and storage (CCS). The suggested refinery system makes use of marine resources, namely seawater, seaweed, and marine microorganisms. Firstly, extensive screening of the current literature was performed to determine which technologies would enable the emergence of such a novel biorefinery system and its merits over conventional refineries. Secondly, the study investigates various scenarios assessing the potential of seaweeds as a means of carbon sequestration. We demonstrate that the removal of 100 Gigatons of excess CO2 using seaweed farms can be achieved in around 4 months to less than 12 years depending on the area under cultivation and the seaweed species. The total bioethanol that could be generated from the harvested biomass is around 8 trillion litres. In addition, high-value chemicals (HVC) that could potentially be recovered from the process represent a considerable opportunity with multi-billion-dollar commercial value. Overall, coastal marine biorefineries have strong potential for a sustainable green economy and represent a rapid approach to climate change mitigation.

The potential of seaweed in increasing revenue of farmer in Bantaeng District

Seaweed farmers have not benefited much from seaweed marketing activities, especially in dry form. Marketing of seaweed in Bantaeng Regency in general has not been maximized, the community has not been able to properly market their seaweed crops. The seaweed cultivating community is tied to traders, where when the community takes seaweed cultivation needs from traders, the farmers are obliged to submit their harvest to the traders, that’s where the trader’s profit plays on the price of seaweed, collectors take seaweed at market prices, so that the price received by farmers far from the general price. The purpose of this study was to analyze the level of income, costs and margins at each of the Cottonii and Gracilaria SP seaweed marketing institutions and to analyze the efficiency strategy for marketing seaweed in Bantaeng Regency. Data analysis was carried out by means of descriptive and quantitative analysis, after which the collected data was tabulated and analyzed. The results of this study are the need for zoning of coastal areas to expand the cultivation area so that seaweed production can increase. The use of technology such as digital marketing and collaboration with the government is expected to help farmers sell their crops.

A Norwegian seaweed utopia? Governmental narratives of coastal communities, upscaling, and the industrial conquering of ocean spaces

Algae-based biomass occupies a prominent role in policy narratives for a more sustainable future situated between Blue Growth Strategies and European (Blue) bioeconomy development. Especially in Norway, the developing seaweed farming sector is portrayed as a novel bioresource sector entailing an array of benefits to remediate global as local environmental and socio-economic challenges. Accredited with massive growth potentials and framed by large-scale industrialist rhetoric with a future in conquering ocean spaces through technological fixes, the sector’s development faces multiple challenges. Additionally, the assumptive growth-centred policy narratives employed leave little room for small-scale, locally embedded alternatives called upon by many experts on sustainable and socially just blue resource governance. The paper addresses this issue by conceptualizing Norwegian seaweed farming as an assembling process with a focus on (policy) narratives as a means for governmental spatial interventions. Based on qualitative data with a focus on active Norwegian seaweed farmers’ perspectives for the sector’s current practices and future developments, the paper assesses the relations and contradictions between the optimistic key policy narratives, current sector developments, and the entrepreneur positionalities that shape the reproduction processes of this Norwegian seaweed assemblage. The paper shows that strong beliefs in extensive growth and technological solutions to tackle the fluid materialities of seaweed production are widespread among entrepreneurs. Paired with policy strategies and a development environment rooted in similar narratives, this creates a current development approach that reduces challenges to technological and administrative domains and neglects the (local) socio-economic and sustainability potential vested in alternative, small-scale approaches.

Home sweet home: Comparison of epibiont assemblages associated with cultivated and wild sugar kelp (Saccharina latissima), co-cultivated blue mussels (Mytilus edulis) and farm infrastructure

Seaweed farming is expanding in Europe and may provide environmental benefits similar to those from natural kelp forests and shellfish farms, including habitat provisioning. Few studies have substantiated these claims however, and it remains uncertain whether seaweed farms will support similar biodiversity to kelp forests or provide valuable long-term habitat beyond the harvest season. We repeatedly surveyed an integrated sugar kelp (Saccharina latissima) and blue mussel (Mytilus edulis) farm in southwest UK to compare epibiont assemblages between cultivated kelps, to those from three nearby wild kelp populations, and to epibionts on farmed mussel lines and unseeded ‘bare’ lines. We found farmed kelps supported over 217 times the abundance of epibionts living on wild kelps at harvest time, however, taxonomic diversity per kelp was lower at the farm. Farmed kelp assemblages were dominated by amphipods, which were present on the wild kelps but in much lower numbers. Farmed kelp also supported distinct assemblages to cultivated mussels, which were similarly dominated by amphipods, but hosted higher relative abundances of crabs, echinoderms, worms and red algal biomass. The bare lines were heavily colonised by another pseudo-kelp, Saccorhiza polyschides, which supported similar epibiont assemblages to the seeded S. latissima lines. Our findings indicate that cultivating bivalves alongside seaweed can increase habitat provisioning at a seaweed farm and extend its permanence beyond typical seaweed cultivation periods as bivalves have longer, continuous farming periods. However, the presence of mussels will likely influence the epibiont assemblages on the farmed kelp, which are distinct from wild kelp populations.

Eucheumatoid seaweed farming in the southern Philippines

Eucheumatoid seaweed farming (ESF) is an important enterprise that provides livelihood opportunities for tropical coastal communities. In this work, we surveyed the current practices of ESF in Tawi-Tawi and Sulu, southern Philippines, where major commercial ESF activities in the country are currently practiced. Seaweed farmers (N = 143) were interviewed using a structured questionnaire containing relevant information on the current farming practices. Results revealed that ESF is one of the primary livelihood sources for coastal inhabitants in the southern Philippines. Most farmers were male, 21–50 years old, and practiced farming for 6–10 years. Farmers mostly owned a farm with an area of 25–400 m2, mainly filled with the rhodophyte elkhorn sea mosses, either Kappaphycus alvarezii or K. striatus. Vegetative cuttings, the major seedling source, were tied using plastic straw into a 6–10 m rope line with a distance interval of 10–20 cm. Inorganic nutrient enrichment is practiced to increase growth and lessen ice-ice disease occurrence. The modified fixed-off bottom (stakes with floaters) is the most predominant farming method. Farms were visited 2–3 times a week for maintenance. Farming is year-round, with peak seasons between August and November. Harvesting is typically done after 21–30 days. Seaweeds are usually dried using the hanging method, which takes 4–6 days. Dried Kappaphycus fronds command higher prices (90–140 PHP/kg) compared to Eucheuma denticulatum (10–50 PHP/kg). Few farmers received government support; therefore, farmers reported many problems affecting their production. This study provides an update on the current ESF practices in the southern Philippines, which have not been well-documented for almost two decades.

Development of Agritourism Based on Seaweed Farming

Nusa Penida Island in Bali has been known as one of popular touristdestinations in Bali. Despite of tourism, Nusa Penida Island waspopular because of the seaweed production. However, the seaweedproduction has declined in this island due to the domination oftourism development. During the Covid-19 pandemic, some peoplein this island have back to seaweed farming. This research aimed tofind out the potential of seaweed farming as an agritourism, and topropose development strategies for agritourism in this island. SuanaVillage was chosen as the location of this research because manyseaweed farming practices are still existed within this village area.Data was collected by using literature review, observation, interviews,and focus group discussion. Data analysis was undertaken by usingInternal-External Factor Analysis, IE Matrix, and SWOT Analysis.Research findings suggested that agritourism based on seaweedfarming at Suana Village has some positive supports in terms oftourist attractions, amenities, accessibility, and ancillary servicesavailable in this village. The IE Matrix analysis suggested that thegrand strategies for the seaweed agritourism development areproduct development and market penetration. It is also required improvement of human resources. This research results show that it is really important to build up competitiveness of development ofseaweed agritourism in order to link tourism and aquaculture inNusa Penida Island.

Global estimates of suitable areas for marine algae farming

Marine algae, both macro and micro, have gained increasing attention for their numerous ecosystem service functions, such as food and raw materials provision and climate change mitigation. Currently, the practice of large-scale algae farming is limited to Asian waters, but significant interest has arisen from other continents. However, there is a lack of knowledge about the areas with suitable environmental conditions for expanding algae farming on a global scale. Previous studies have primarily focused on nutrient availability and thermal constraints when assessing the potential for algae culture. This study uses species distribution models based on an ensemble consensus approach to determine the extent of suitable areas and takes into account multiple environmental factors that may affect the feasibility of algae culture. Our results show that approximately 20.8 million km2 of the ocean (∼13.8% of the economic exclusive zones) is suitable for farming marine algae species, with most potential areas located near the coastline. Surprisingly, four out of the top five countries with the largest area suitable for seaweed farming, including Australia, Russia, Canada, and the US, account for 30% of the total suitable areas, yet they currently produce less than 1% of the global seaweed. Several species show promising characteristics for large-scale cultivation, but their viability for commercial production remains uncertain and subject to further assessment of economic feasibility and social acceptance. Further research on the ecological benefits of seaweed farming could also promote the development of an ecologically friendly and financially viable algae mariculture industry. This study provides a scientific basis for decision-makers to understand potential expansion areas and feasible pathways for seaweed farming, with the ultimate goal of ensuring the sustainable utilization of marine resources.

The IUCN Global Standard for Nature-based Solutions™ as a tool for enhancing the sustainable development of marine aquaculture

This paper applies the IUCN Global Standard for Nature based Solutions™ self-assessment tool (published in 2020) to two aquaculture case studies. Data from the case studies were compiled by the authors. In Zanzibar, secondary data were obtained through a previous project, which included a stakeholder workshop in Zanzibar (in 2019) and one deliverable published by the IUCN on Zanzibar of their catalogue “Aquaculture and Marine Conservation”. In Indonesia, the original data were provided by the Blue Natural Capital Funding Facility (BNCFF) and the associated local teams. The analysis of the data, the information provided, and the scoring itself were done by the authors, in association with local teams in both areas. The results of the two assessments, discussed in the paper and presented in detail in the Supplementary materials, can be considered original research, never previously published in a scientific journal. The concept of Nature-based Solutions (NbS) was proposed by the International Union for Conservation of Nature (IUCN) to protect, restore, and sustainably manage natural and modified ecosystems for achieving a variety of societal benefits. The IUCN released the IUCN Global Standard for NbS™ to help design, assess, strengthen, and upscale NbS interventions. In the current context of growing uncertainties for the future of coastlines and oceans, aquaculture has been recognized as a positive activity for achieving sustainable development in coastal communities; supporting food security, poverty alleviation, and economic resilience; and contributing to the conservation of marine ecosystems in some cases. However, the sustainability of aquaculture systems has often been criticized. Aquaculture initiatives in coastal areas can achieve both nature conservation and sustainable development objectives, but reflection on the conditions under which this would happen is needed. This article examines aquaculture systems through the lens of the NbS concept and the IUCN Global Standard for NbS™, along with other sustainability concepts and instruments currently used in the context of aquaculture. The application of the IUCN Global Standard for NbS™’s to two case studies is explored: seaweed farming in Zanzibar in marine conservation areas and shrimp farming coupled with mangrove restoration in Indonesia. The results show that the NbS concept underpinning the IUCN Global Standard for NbS™ could help in the overall assessment of aquaculture systems and improve their sustainability by highlighting both their positive outcomes and issues requiring further examination in relation to marine biodiversity benefits, socio-economic development, and/or governance. The IUCN Global Standard for NbS™ could provide an operational framework to implement existing concepts, such as the Ecosystem Approach to Aquaculture, contribute to clarifying critical issues in aquaculture development, and provide guidance for the development of a new type of aquaculture project, specifically designed as NbS. This finding advocates the context-dependent exploration and promotion of aquaculture projects as NbS.

Accurate mapping of seaweed farms with high-resolution imagery in China

Seaweed aquaculture is vital in protecting the marine eco-environment and mitigating climate change. China generates more than half of the world’s total seaweed production. However, despite multiple local studies, accurate and reliable information on broad-scale seaweed farms is still scarce. Using an object-based method to classify 3 m spatial resolution Planet Scope images along offshore China, a total of 129,494 ha of cultured seaweed was identified and delineated with an overall accuracy of 95.70% and a KAPPA index of 0.912, respectively. Then, a seaweed map in offshore China in 2018–2019 was developed. The results provided basic information about seaweed farms in China. The approach reported in this work is accurate and efficient, which can be used to replace the conventional method to obtain the culture seaweed information. This study can be of reference for mapping seaweed on a broader or global scale.

Production of Ulva fasciata biomass through optimization of culture condition for viable tank-based edible seaweed farming

Production of Ulva fasciata biomass through optimization of culture condition for viable tank-based edible seaweed farming